The state of the art power management for electronics is growing increasingly complex, dealing with more sensitive components occupying smaller space and having high speed devices operating at relatively low power. There may be multiple power sources on certain systems and varied loads.
In general, DC power supply systems for current electronics require highly regulated DC power supplies. There are various protective circuits including over voltage, over current, under voltage and thermal.
One of the well-documented problems with various regulated DC supplies pertains to the over-voltage protection topology. An output over voltage from the voltage regulator section can seriously damage the various electronic circuits coupled to that power source. The over voltage protection is typically triggered by noise or actual over voltage situations.
There have been various attempts to counter the over voltage conditions and various mechanisms to employ such as the crowbar circuit. Crossbars are generally expensive and are relevant for large current loads and expensive electronic devices. Other over protection schemes include pulse width modulated circuits in conjunction with latched logic to turn off the gating FET devices. These latter over voltage protection schemes tend to generate large negative spikes that may damage the circuitry.
What is needed is an over-voltage condition system that senses an over voltage condition and responds accordingly such that no negative spike is generated.